聚乙烯醇在二元和三元共聚乳液中的作用

本文通过实验讨论了ＰＶＡ对ＶＡＣ／ＭＭＡ二元共聚乳液性能的影响及对ＶＡＣ／ＢＡ／ＭＭＡ三元共聚乳的作用。     

丙烯腈/醋酸乙烯酯/甲基丙烯磺酸钠共聚体系竞聚率的研究

利用核磁共振技术测定共聚物组成,用Ｍａｙｏ－Ｌｅｗｉｓ共聚物组成方程拟合实验数据计算竞聚率。得到的丙烯腈／醋酸乙烯酯（ＡＮ／ＶＡｃ）本体共聚的竞聚率数据用于分析间歇聚合反应试验,理论计算与试验数据吻合。并研究了丙烯腈／醋酸乙烯酯／甲基丙烯磺酸钠（ＡＮ／ＶＡｃ／ＳＭＡＳ）三元水相共聚反应体系的特征,测定了该三元共聚体系表观竞聚率     

合成CR／MMA—AA三元接枝型胶粘剂新方法的研究

本文叙述了以氯丁橡胶、甲基丙烯酸甲酯和丙烯酸为反应物质，在以五种有机化合物组成的混合溶剂中进行三元接枝共聚合反应，合成ＣＲ／ＭＭＡ－ＡＡ三元接枝型胶粘剂的新工艺过程。     

合成CR／MMA－AA三元接枝型胶粘剂新方法的研究

本文叙述了以氯丁橡胶、甲基丙烯酸甲酯和丙烯酸为反应物质，在以五种有机化合物组成的混合溶剂中进行三元接枝共聚合反应，合成ＣＲ／ＭＭＡ－ＡＡ三元接枝型胶粘剂的新工艺过程。     

无三苯鞋用胶的研制

在无三苯混合溶剂下,采用复合引发剂,合成Ａ－９０／ＭＭＡ／ＡＡ三元接枝氯丁胶,并配以高性能增粘树脂,制备出高性能环保型鞋用胶。     

AM／AMPS／AMC16S共聚物的合成与性能

采用氧化－还原引发体系合成了丙烯酰胺（ＡＭ）／２－丙烯酰胺基－２－甲基丙磺酸（ＡＭＰＳ）／２－丙烯酰胺基十六烷磺酸（ＡＭＣ１６Ｓ）三元共聚物，借助红外光谱和差热分析测定了基结构和热稳定性，初步评价了共聚物的溶液性能，结果表明：ＡＭ／ＡＭＰＳ／ＡＭＣ１６Ｓ共聚物热稳定性好，耐温抗盐能力强。     

AM／AMPS／AMC12S共聚物的合成与性能

采用氧化－还原引发体系合成了丙烯酰胺（ＡＭ）／２－甲基丙磺酸（ＡＭＰＳ）／２－丙烯酰胺基十二烷磺酸三元共聚物。借助红外光谱和热分析研究聚合物的结构和热稳定性,初步评价了共聚物的溶液性能。结果表明,ＡＭ／ＡＭＰＳ／ＡＭ１２Ｓ共聚物热稳定性好,耐温抗盐能力强。     

AA／AMPS／HPA共聚物的合成及性能评定

介绍了丙烯酸（ＡＡ）－２－丙烯酰胺－２－甲基丙磺酸（ＡＭＰＳ）－丙烯酸羟丙酯（ＨＰＡ）三元共聚物的合成方法,并对其阻垢缓蚀性能进行了研究。结果表明,ＡＡ／ＡＭＰＳ／ＨＰＡ共聚物具有优良的阻垢缓蚀性能,是一种具有发展前途的新型高效水质稳定剂。     

中国合成树脂及塑料文摘

每期文摘的题目均按汉语拼音顺序排列，英文按其字母顺序排列在汉字之前，数字开头的题目排在最前面。　　ＡＳ／ＭＢＳ／ＥＶＡ三元共混体系力学性能及微观形态／冯汇（中山大学高分子研究所）／现代塑料加工应用。1999，11（1）：6～ 8。研究了ＡＳ／ＭＢＳ／ＥＶＡ三元共混体系的力学性质和微观形态。采用ＥＶＡ为相容剂改善核壳型粒子ＭＢＳ在ＡＳ基体中的分散，达到良好效果，在保持良好弯曲性能的同时，提高了基体的缺口冲击强度。ＡＳ／ＭＢＳ／ＳＢＲ的力学性能及其微观形态／冯汇（中山大学高分子研究所）／塑料工业。1999，2 7（1…     

N,N-二乙基丙烯酰胺及其共聚物的合成

首先合成了Ｎ,Ｎ－二乙基丙烯酰胺,并采用氧化－还原引发体系,合成了丙烯酰胺（ＡＭ）／２－丙烯酰胺基－２－甲基丙磺酸（ＡＭＰＳ）／Ｎ,Ｎ－二乙基丙烯酰胺（ＤＥＡＭ）三元共聚物。通过元素分析和红外光谱分析了ＤＥＡＭ的结构,用红外光谱和热分析研究了聚合物的结构与热稳定性,初步评价了共聚物的溶液性能。结果表明,ＡＭ／ＡＭＰＳ／ＤＥＡＭ共聚物具有较好的热稳定性和耐温抗盐能力。     

AM/AN/ANPE共聚物的合成研究

采用自由基胶束聚合法合成了丙烯酰胺(AM)/丙烯腈(AN)/烯丙基(对-壬基)苯基醚(ANPE)疏水缔合型水溶性共聚物,研究得到了适宜的聚合条件,AM、AN、ANPE、SDS和AIBN用量相对于溶剂总量的质量分数分别为26%、4.8%、0.60%、2.0%和0.20%～0.26%,K2S2O6/NaHSO3引发剂的浓度为40~130μmol/L,反应温度55℃~65℃,反应时间为7 h。     

Probing the mechanistic aspects of the chromium salen catalyzed carbon dioxide/epoxide copolymerization process using in situ ATR/FTIR

Studies of the copolymerization of CO₂ and epoxides have been the staple of our group's research program for the better part of a decade now. During that time, the incorporation of attenuated total reflectance Fourier transform infrared (ATR/FTIR) spectroscopy has greatly enhanced the kinetic and mechanistic investigations performed. However helpful, there are some difficulties, e.g., phase partitioning, that we have discovered and overcome in that same time period. The greatest step forward was achieved by the incorporation of 2-(3,4-epoxycyclohexyl)-ethyltrimethoxysilane (TMSO) as an epoxide for performing accurate kinetic studies. Herein, we discuss the development of this technique into one of the mainstays within our laboratories, highlighted by our most recent catalyst system that utilizes (salen)Cr^IIIX/cocatalyst where salen: N,N′-bis(salicylidene)-1,2-ethylenediimine, X: Cl⁻ or N₃⁻ and cocatalyst: N-methylimidazole, phosphines and PPN⁺ salts. Through altering the cocatalyst, ligand architecture and initiator, this catalyst system has proven to be one of the most industrially viable catalysts currently being studied.     

Effect of Zr-Modified SiO2-Supported Metallocene/MAO Catalyst on Copolymerization of Ethylene/1-Octene

The study revealed enhancement (four to seven times) of catalytic activities for ethylene/1-octene copolymerization via the Zr-modified SiO₂-supported the metallocene/MAO catalyst. Increased activity can be attributed to an increase in absorption ability of MAO on the modified support. In addition, the strong interaction between MAO and the support was also considered.     

Properties of polymer/clay interphase in nanoparticles synthesized through in-situ polymerization processes

This article is devoted to the effects of the presence of modified clays during in-situ polymerization. Such synthesis routes require clay modifications in order to render the clay surface compatible with the monomer-polymer and/or reactive during polymerization. In addition, the use of nanometric clays (laponite) induces a large surface area which introduces the differentiation between the polymer located in the clay vicinity (interphase) and the bulk polymer. Composite nanoparticles obtained from in-situ emulsion and from in-situ-miniemulsion polymerizations and simple blends of pure polymer latex and unmodified clays were used to prepare free-standing films. The behavior of these composite films has been compared in terms of shifts in relaxation temperature (assessed by Dynamic Mechanical Analysis), in monomer composition (assessed by Nuclear Magnetic Resonance analysis) and in molecular weight (assessed by Gel Permeation Chromatography). It has been demonstrated that both nanocomposites obtained by in-situ polymerization show a modification of the relaxation process due in the case of emulsion to a composition drift in the vicinity of the clay, and in the case of miniemulsion to a plasticizing effect of the numerous short copolymer chains generated at the clay surface.     

PET／DEG／TA和PET／DEG／MA不饱和聚酯树脂固化研究

本文讨论了分别用顺酐和反酸与聚酯合成不饱和聚酯树脂的反应机理,并分析了二种树脂体系固化放热曲线出现差异的原因在于固化交联时不饱和双键的活性不同。     

苯丙共聚物乳液合成研究

以苯乙烯,丙烯酸酯类为共聚单体,采用乳液聚合合成了低成本的苯丙共聚乳液。讨论了单体共聚比,ｐＨ调节剂,乳化剂等对乳液聚合的影响。     

Helical conformation of the copolymers of l-proline derivatives based propargylether and chiral N-propargylamide

The novel acetylene monomers, l-proline derivatives based propargylethers PR (PA, PC, and PL) were synthesized by alkylation of Boc-hydroxyproline with propargyl bromide and acylation of achiral amine. The homopolymers of the novel acetylene monomer exist in no regulated higher order structure in solvents because of the lack of hydrogen bond and the unique ring structure in the pendant. Consequently, the copolymerization of l-proline-derived chiral propargylether PR with the l-alanine-derived N-propargylamide (LA) was formed and the chiroptical properties of the formed copolymers were examined. We conclude that (1) N-H of the amide group at 2-position in proline play an important role in the formation of helical conformation of poly(LA₈₈-co-PR₁₂); (2) improving the amount of PC of poly(LA-co-PC) changes the conformation of the copolymer in CHCl₃ and perturbs the leadership of LA; (3) the conformation of poly(LA₇₅-co-PC₂₅) remarkably changes with changing temperature and PC obtains the leadership in the competition on the conformation of poly(LA₇₅-co-PC₂₅) in CHCl₃ with the improvement of temperature.     

SBS／MMA—BA自交联型接枝共聚物及其性能研究

在交联单体Ｎ－ＭＭＡ存在下，研究了ＳＢＳ／ＭＭＡ－ＢＡ四元枝共聚反应及其产物性能，讨论了引发剂浓度、Ｎ－ＭＭＡ用量、单体配比、反应时间及反应温度对接枝聚合影响，获得了最佳合成工艺条件。通过红外光谱和ＰＶＣ／ＳＢＳ粘接性能测试表明，共聚物具有初粘力大、剥离强度高、使用方便等特点。     

Polymerization of ionic monomers in polar solvents: kinetics and mechanism of the free radical copolymerization of acrylamide/acrylic acid

A precise data set describing the kinetics of the free radical copolymerization of acrylamide/acrylic acid (AM/AA) in the range of low total monomer concentration as a function of the pH, total monomer concentration, initiator concentration, and comonomer ratio is presented. Strong impact on the reactivity ratios has been identified for the pH and total monomer concentration. Specifically, at constant total monomer concentration of 0.4 mol/l and T=313 K the reactivity ratio of AM increases from 0.54 at pH 1.8 to 3.04 at pH 12. Contrarily, the reactivity ratio of AA decreases from 1.48 to 0.32. The crossover occurs at pH≈4.2. Electrostatic effects due to the variation of the degree of ionization of AA are primarily suggested to influence the kinetics. When the total monomer concentration increases from 0.2 to 0.6 mol/l at constant pH=12, the reactivity ratios of AM and AA decrease from 4.01 to 2.13 and increase from 0.25 to 0.47, respectively. Reduction of electrostatic repulsion between the ionized monomer AA and partially charged growing polymer chain ends due to higher ionic strength at higher total monomer concentration serves as explanation of the effect. The precise data set is the prerequisite for a novel approach to calculate copolymer compositions in case of variable monomer reactivity.     

Copolymerization of CO2 and propylene oxide under rare earth ternary catalyst: design of ligand in yttrium complex

Copolymerization of carbon dioxide and propylene oxide was carried out employing (RC₆H₄COO)₃Y/glycerin/ZnEt₂ (R=-H, -CH₃, -NO₂, -OH) ternary catalyst systems. The feature of yttrium carboxylates (ligand, substituent and its position on the aromatic ring) is of great importance in the final copolymerization. Appropriate design of substituent and position of the ligand in benzoate-based yttrium complex can adjust the microstructure of aliphatic polycarbonate in a moderate degree, where the head-to-tail linkage in the copolymer is adjustable from 68.4 to 75.4%. The steric factor of the ligand in the yttrium complex is crucial for the molecular weight distribution of the copolymer, probably due to the fact that the substituent at 2 and 4-position would disturb the coordination or insertion of the monomer, lead the copolymer with broad molecular distribution. Based on the study of ultraviolet-visible spectra of the ternary catalyst in various solvents, it seems that the absorption band at 240-255 nm be closely related to the active species of the rare earth ternary catalysts.